A retrospective study evaluating the influence of time to chemotherapy on patients with triple-negative disease and its impact on survival outcome has found that patients who delayed adjuvant chemotherapy more than 30 days after surgery had a significantly higher risk for disease recurrence and death compared with patients who underwent treatment within the first 30 days following surgery. The greater the delay, the worse the outcome. According to the study results, delays in receiving adjuvant chemotherapy initiation in this high-risk group of patients should be avoided. The study by Morante et al was presented at the 2018 San Antonio Breast Cancer Symposium (Abstract GS2-05).
Previous studies have shown that, overall, adjuvant chemotherapy decreases the risk recurrence and improves survival rates in patients with breast cancer. However, information was lacking on whether delaying the initiation of adjuvant chemotherapy affects outcomes, especially in patients with triple-negative breast cancer.
Study Methodology and Results
The researchers retrospectively analyzed data obtained from the medical records of 687 patients with stage I to III triple-negative breast cancer who had undergone surgery and later received either anthracyclines or anthracyclines plus taxane-based chemotherapy. The patients’ mean age at diagnosis was 49.15. The median follow-up was 101 months, and the median time to chemotherapy was 41 days. The researchers found that 189 patients received chemotherapy at or before 30 days after surgery; 329, between 31 and 60 days; 115, between 61 and 90 days; and 54 started chemotherapy beyond 90 days after surgery.
The researchers found that as the time to starting adjuvant chemotherapy increased, the 10-year disease-free survival rate decreased: 81.4%, 68.6%, 70.8%, and 68.1% among patients who received chemotherapy at ≤ 30, 31–60, 61–90, ≥ 91 days, respectively (P = .005). The 10-year overall survival rate also decreased as the time to starting adjuvant chemotherapy increased: 82%, 67.4%, 67.1%, and 65.1% among patients who received chemotherapy at ≤ 30, 31–60, 61–90, ≥ 91 days, respectively (P = .003).
In their multivariate analysis of how the extent of delay in starting chemotherapy impacted an increased risk for disease recurrence and death, the researchers found time to chemotherapy was an independent prognostic factor for recurrence-free survival and overall survival. Patients with a time to chemotherapy of 31–60 days (hazard ratio [HR] = 1.92; 95% confidence interval [CI] = 1.225–2.998); 61–90 days (HR = 2.38; 95% CI = 1.354–4.172); and ≥ 91 days (HR = 2.47; 95% CI = 1.250–4.886) had worse survival compared with those who initiated treatment in the first 30 days after surgery. Patients with a time to chemotherapy of 31–60 days (HR = 1.94; 95% CI = 1.243–3.034), 61–90 days (HR = 2.45; 95% CI = 1.402–4.265), and ≥ 91 days (HR = 2.79; 95% CI = 1.418–5.506) had worse survival compared with those who initiated treatment in the first 30 days after surgery.
Risk of Delaying Treatment
“Our data show that it must be a priority for patients with triple-negative breast cancer to begin adjuvant chemotherapy within 30 days of completing surgery,” said Zaida Morante, MD, a medical oncologist at Instituto Nacional de Enfermedades Neoplásicas in Lima, Peru, and the lead author of this study, in a statement. “After this period of time, the benefit of the chemotherapy is significantly diminished.”
Disclosure: See the study authors’ full disclosures at sabcs.org.
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